The week began with President Obama on the tarmac of a military base in Maryland, waiting to welcome a global celebrity far more popular than he. It ended with him raising a toast to a hard-nosed world leader who has repeatedly challenged American interests and Obama’s resolve.

Along the way, the president’s most frequent legislative sparring partner in Washington relinquished his post on Capitol Hill, finally surrendering to the sharp polarization that has come to define American politics in the past five years. And abroad, another of Obama’s persistent antagonists — the Russian president — suddenly wanted a face-to-face chat about Syria and Ukraine.

The week’s events seemed like political surrealism. When Pope Francis arrived at the White House on Wednesday, the weather was so gorgeous it put Obama in a hopeful, reverential mood.